Last-minute shoppers 'to spend $3.3bn'

Australians are expected to spend around $3.3 billion in the two days before Christmas as shoppers take advantage of extended retail hours.

The figure is part of $8 billion predicted by the Retail Council to be spent by shoppers in the seven days to December 25.

About $1.2 billion was tipped to be spent on food and drink for Christmas festivities in the days leading up to the big day, according to NAB.

NAB has forecast its customers will spend about $20 million more this year on food and drink compared with last year.

"Interestingly, unlike in previous years, we've seen customers shopping over longer periods of the day - with transaction volumes remaining very high up until 6pm," NAB executive general manager of consumer lending Angus Gilfillan said in a statement on Friday.

"This is likely due to longer trading hours."

Some businesses across the country are opening their doors for a marathon 36 hours to accommodate the last-minute rush.